1. Field of the Invention
The present invention relates generally to a power converter, and in particular to a power converter comprising an output voltage level indicating device for indication and easy reading of output level of voltage.
2. Description of the Prior Art
Portable electronic appliances, such as mobile phone and notebook computer, play an important role in the modern world in doing business and society activities. Such portable appliances are often powered by built-in power sources, which must be constantly recharged in order to maintain operability of the portable appliances. Also, external powering is also available for most of the portable appliances, such as wall outlet, automobile electrical system including cigarette lighter socket and electrical socket regularly available in airplanes. Often the external powering must be converted by for example a conversion circuit made in the form of an adaptor before it can be supplied to the portable appliances.
However, the portable appliances are often operated with different working voltages and for such a reason, the general consumers that own and use two or more different portable appliance must regularly bring two or more adaptors corresponding to those portable appliances. This complicates the use of the portable appliances and is very troublesome to the consumers. U.S. Pat. No. 6,628,535, issued to the present inventor, teaches a power converter that provides selectable output voltage levels to different appliances or loads. The power converter of the '535 patent comprises an output to which a terminal connector is selectively coupled. The terminal connector comprises a circuit comprised of resistors that generates a feedback signal to a control circuit of the power converter, inducing a corresponding voltage level at the output of the conversion device.
Such a conventional power converter works well in supplying voltage of different levels to electronic appliances that operates with different working voltages. It, however, is still unclear to a user what voltage level is being output by the power converter when the device is powering an electronic appliance. This may cause problem to the user.
Thus, the present invention is aimed to provide a power converter that overcomes the drawback of the conventional devices.